NAME

       unw_get_proc_info_by_ip -- get procedure info by IP

SYNOPSIS

       #include <libunwind.h>

       int unw_get_proc_info_by_ip(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pip, void *arg);

DESCRIPTION

       The unw_get_proc_info_by_ip() routine returns the same kind of auxiliary information about a procedure as
       unw_get_proc_info(),  except  that the info is looked up by instruction-pointer (IP) instead of a cursor.
       This is more flexible because it is possible to look up the info for an arbitrary procedure, even  if  it
       is  not  part  of the current call-chain. However, since it is more flexible, it also tends to run slower
       (and often much slower) than unw_get_proc_info().

       The routine expects the followins arguments: as is the address-space  in  which  the  instruction-pointer
       should  be  looked  up.  For a look-up in the local address-space, unw_local_addr_space can be passed for
       this argument.  Argument ip is the instruction-pointer for which the procedure info should be  looked  up
       and  pip  is  a pointer to a structure of type unw_proc_info_t which is used to return the info.  Lastly,
       arg is the address-space argument that should be used when accessing the address-space. It has  the  same
       purpose  as  the argument of the same name for unw_init_remote().  When accessing the local address-space
       (first argument is unw_local_addr_space), NULL must be passed for this argument.

       Note that for the purposes of libunwind, the  code  of  a  procedure  is  assumed  to  occupy  a  single,
       contiguous  range  of  addresses.  For  this  reason,  it  is  alwas possible to describe the extent of a
       procedure with the start_ip and end_ip members. If a single  function/routine  is  split  into  multiple,
       discontiguous pieces, libunwind will treat each piece as a separate procedure.

RETURN VALUE

       On successful completion, unw_get_proc_info_by_ip() returns 0. Otherwise the negative value of one of the
       error-codes below is returned.

THREAD AND SIGNAL SAFETY

       unw_get_proc_info()  is thread-safe. If the local address-space is passed in argument as, this routine is
       also safe to use from a signal handler.

ERRORS

       UNW_EUNSPEC
               An unspecified error occurred.

       UNW_ENOINFO
               Libunwind was unable to locate unwind-info for the procedure.

       UNW_EBADVERSION
               The unwind-info for the procedure has version or format that is not understood by libunwind.

       In addition, unw_get_proc_info() may return  any  error  returned  by  the  access_mem()  call-back  (see
       unw_create_addr_space(3)).

SEE ALSO

       libunwind(3), unw_create_addr_space(3), unw_get_proc_name(3), unw_get_proc_info(3), unw_init_remote(3)

AUTHOR

       David Mosberger-Tang
       Email: dmosberger@gmail.com
       WWW: http://www.nongnu.org/libunwind/.

Programming Library                              16 August 2007                       UNW_GET_PROC_INFO_BY_IP(3)